Forensic DNA Profiling

DNA testing and its forensic analysis are recognized as the "gold standard" in forensic identification science methods. However, there is a great need for a hands-on step-by-step guide to teach the forensic DNA community how to interpret DNA mixtures, how to assign a likelihood ratio, and how to use the subsequent likelihood ratio when reporting interpretation conclusions.

Forensic DNA Profiles: A Practical Guide to Assigning Likelihood Ratios will provide a roadmap for labs all over the world and the next generation of analysts who need this foundational understanding. The techniques used in forensic DNA analysis are based upon the accepted principles of molecular biology. The interpretation of a good quality DNA profile generated from a crime scene stain from a single source donor provides an unambiguous result when using the most modern forensic DNA methods. Unfortunately, many crime scene profiles however are not single source. They are described as mixed since they contain DNA from two or more individuals. Interpretation of DNA mixtures represents one of the greatest challenges to the forensic DNA analyst.

As such, the book introduces terms used to describe DNA profiles and profile interpretation. Chapters explains DNA extraction methods, the Polymerase Chain Reaction (PCR), Capillary Electrophoresis (CE), likelihood ratios (LRs) and their interpretation, and population genetic models-including Mendelian inheritance and Hardy-Weinberg Equilibrium. It is important that analysts understand how LRs are generated in a probabilistic framework, ideally with an appreciation of both semi-continuous and fully-continuous probabilistic approaches.

Key features:

• The first book to focus entirely on DNA mixtures and the complexities involved with interpreting the results
• Takes a hands-on approach offering theory with worked examples and exercises to be easily understood and implementable by laboratory personnel
• New methods, heretofore unpublished previously, provide a means to innovate deconvoluting a mixed DNA profile, assign an LR, and appropriately report the weight of evidence
• Discusses various topics of debate within the forensic DNA community, including a section addressing stochastic effects and low-level DNA

Forensic DNA Profiles fills the void for labs unfamiliar with LRs, and moving to probabilistic solutions, and for labs already familiar with LRs, but wishing to understand probabilistic methods in more detail. The book will be a welcome read for lab professionals and technicians, students, and legal professionals seeking to understand and apply the techniques covered.